Method and means for forming impressions for full lower dentures



1955 F. BLAIR ET AL 2,700,217

METHOD AND MEANS FORMING IMPRESSIONS FOR L ER DENTURES F Sept. 8, 1953 INVENTORS: BLAIR FRANK FRANK J. TRAXL United States Patent 0 METHOD AND NIEANS FOR FORMING IMPRESSIONS FOR FULL LOWER DENTURES Frank Blair and Frank J. Traxl, Chicago, Ill., assignors of one-third to William A. Snow Application September 8, 195;), Serial No. 378,995

7 Claims. (Cl. 32-17) This invention relates to improvement in impression devices for full lower dentures and a new and improved method of forming such impressions.

Heretofore it has been common procedure to employ a metal U-shaped tray having a trough therein in making lower denture impressions. The area of the tray was greater in width than the distance between the mandibular-ridge where the third molars were formerly positioned. This caused distending of the cheek, jaw, lingual, buccal and labial muscles when the device was inserted in the mouth to the detriment of obtaining a true and representative impression of the mandibular-ridge and surrounding areas in a natural or at rest position. Also the tray trough was filled with impression material to its peripheries, inverted and inserted in the mouth by the dentist, pressed down against the mandibular-ridge and held there by him, usually with his fingers until the material hardened. This also meant keeping the mouth widely opened and keeping the tongue well up in the roof of the mouth causing the lingual, buccal, labial and tongue muscles to be unduly stretched, thereby creating an imperfect impression, requiring much more time by the dentist to properly adjust the subsequent denture, made from the impression taken in this manner. This foregoing procedure was likewise, very uncomfortable and disagreeable to the patient. It is, therefore, the main object of the present invention to overcome the foregoing inherent defects.

Other objects of this invention are to provide a new and improved technique in producing impressions for full lower dentures; to provide a device for accomplishing this technique which is extremely simple in construction; to provide a device of this character which enables the mouth muscles, particularly the buccal and labial muscles to be at a natural rest position, and simultaneously depressing the lingual muscles during the process of forming a full lower denture impression; to provide a device of this character which will automatically be held in position during the impression forming by the maxilla or the hard palate of the mouth; and to provide a device of this character which is extremely comfortable to the patient during the making of an impression.

An illustrative embodiment of this invention is shown in the accompanying drawings in which:

Figure l is a top elevational view of the device of the present invention in position in the mouth, the lower mandibular-ridge being shown in elevation while some of other parts of the mandible and associated tissues being shown in section.

Figs. 2 and 3 are cross section views taken on the lines 22 and 3--3 respectively of Fig. 1. In Fig. 3 the representation of the human tongue is removed for clarity.

Fig. 4 is a perspective view of the device of our invention.

Referring in detail to the drawing, the device of the present invention comprises a substantially U-shaped dam, generally indicated by the letter D, having a pair of side walls 1 and 2 and an end or front wall 3. It is to be noted that the distal or free ends of the walls 1 and 2 slightly flare outwardly so that when in position in the floor of the mouth, they will abut against the gums at a point slightly beyond where the usual third molar would have been, had it not been extracted. (See Fig. 1.) It is also to be noted the walls 1 and 2 are slightly arcuate in shape and both the upper and lower surfaces of all the walls are rounded. It will also be noted from Figs. 2 and 4, that the lower surface of wall 3 is cut away as at "ice 4 to accommodate the forward end of the lingual frenum and sublingual gland and allow the front wall 3 to lie closely adjacent to the posterior portion of the mandibular ridge where the usual incisor teeth were positioned.

An elongated bore or seat 5 is positioned in the upper surface of the front wall 3 to accommodate a post, generally indicated by the letter P, which comprises a pin 6 on which a bulbous-like or enlarged head 7 is formed. The pin 6 is removably seated in the bore 5. The top 8 is rounded so that the hard palate may comfortably rest thereon as shown in Fig. 2, when the device of our invention is in use.

In use the dam is inserted in the mouth and positioned on the floor thereof in the position shown in the drawing, the pin 6 is inserted in the bore 5 and upper maxilla closed until the hard palate rests on the head 8 of the post. The muscles of the floor of the mouth and lingual muscles are now automatically depressed. This is desirable as they are now out of the way so as to obtain a perfect impression of the lingual mandibular area. The tongue also is now slightly elevated and retracted and can lie on the upper edge of the walls 1 and 2 and therebetween. The labial muscle area is generally indicated at 9, and the buccal muscle area is generally indicated at 10. These muscles are all relaxed because they are not distorted or stretched. All of this is accomplished because the mouth -is only slightly opened and there is substantially no muscle distortion of any kind.

The importance of having relaxed, buccal and labial muscles is extremely important because these muscles play an important part in retaining the finished denture in position on the mandibular ridge.

The impression material M is now poured or placed into the mouth by flowing the same in the areas between the inner wall of the cheeks 12 and lip 13, and the outer faces of walls 1, 2 and 3, to completely cover the gums 14 to substantially the height of the dam. The application of the impression material to the mouth can be accomplished by any suitable means but the most facile manner would be by means of a pressure gun having a long nozzle for comfortable insertion in the mouth of the patient, where the impression material in a plastic state can be directed with precise accuracy to the parts or voids to be filled.

When the impression material has set, the post D is first removed from the dam, and then the dam and the set impression material removed from the mouth.

The device of the present invention has been actually used many times on patients and found to be (1) extremei ly more comfortable from the patient stand-point than former known methods; (2) easier for the dentist to use and a great deal less time is consumed to obtain a lower denture impression, time being of the essence because of the fast setting characteristics of the impression mate- 1 rial; (3) a more accurate and truer impression is made;

(4) the technician and dentist are able to fabricate a full lower plate denture in a better and more facile manner than heretofore; and (5) the resultant denture is a better fitting one for the patient, with substantially no extra visits to the dentist for refitting when once fitted and in use.

Although but one specific embodiment of this invention is herein shown and described, it will be understood that numerous details of the construction shown may be r altered or omitted without departing from the spirit of the invention as defined by the following claims.

We claim:

1. A denture device of the class described comprising a substantially U-shaped darn member, adapted to seat in the floor of the mouth and substantially follow the contour shape of the mandibular ridge line of the human mouth on the lingual side of said mandibular ridge and spaced inwardly therefrom, the legs of said darn diverging from the anterior and posterior centerline between the lower mandibular ridge to substantially contact the gums at their free ends, and said dam having a rounded front wall, a post projecting vertically upwardly from the top surface of said front wall of said dam for engagement by the hard palate of the mouth.

2. The device according to claim 1 wherein the legs of said dam are arcuate shaped.

3. The device according to claim 1 wherein the. lower surface of said front wall is cut away to bridge the forward portion of the lingual frenum and sublingual gland and position said. front wall closely adjacent to the mandibular ridge in the anterior; part. of the mouth.

4. The device according. to claim 1 wherein said post is removably secured. to said damand comprises a pin, and bulbous-like head, said front wall having a vertical bore in its upper surface for the seating. of said pin.

5. A denture device of the class described comprising a substantially U-shaped dam member adapted to seat in the floor of the mouth and substantially follow the contour shape of the lower mandibular ridge line of'thehuman mouth on the lingual side of said mandibular ridge line and spaced inwardly therefrom, the legs of said dam diverging from the anterior; and posterior centerline between the lower gums. to substantially contact the gums at their free ends at a point slightly beyond the thirdrnolar position of the, teeth, said walls having a slight radius, said dam having a rounded front wall, the lower surface of said front wall being. cut away to bridge the front or forward portion of the lingual frenum and sublingual gland and position said front wall closely adjacent to the mandibular ridge line adjacent the anterior part of the mouth, said front wall having a vertical bore in its top surface, and a post for said dam comprising a pin and head, said pin, removably seated. in said bore and the top surface of said head engaging the hard palate of said mouth.

6. The method of forming full lower denture impressions for the human mouth which comprises placing a substantially U-shaped' dam having side walls and a rounded front wall in the floor of the mouth of a human being and positioned so that the walls substantially follow the lower mandibular ridge on the lingual side and spaced therefrom and in such a manner that the side walls willdivcrge from the, anterior and posterior centerline between the lower mandibular ridge and the free ends thereof will substantially abut the mandibular ridge at a point substantially where the third molars are usually positioned in the mandibular ridge, then retaining said dam in operative position by a vertical post which is engaged by the hard palate of the month while the buccal and labial muscles are relaxed, and the muscles of the mouth and the lingual muscles are depressed by said dam, then flowing a semi-liquid impression material into the area between the inner walls of the cheeks and lower lip, and the buccal and labial sides of the mandibular ridge respectively, over the mandibular ridge and in the area between, the lingual side of the mandibular ridge and the outer walls of the darn, allowing the impression material to set, then after the impression material has set, removing1 the post and then the dam and set impression materia.

. 7. The method of forming a lower dental impression while the labial and buccal muscles are substantially completely relaxed, which consists in placing a dam on the floor of the mouth in a manner wherein the dam is spaced from the mandibular ridge line and foliows the contour of the mandibular ridge, line and held in, operative position by the hardpalate of the mouth, and simultaneously depressing the lingual muscles, and museies of the floor of the month, then flowing impression material in the area between the inner walls of cheeks and lower lip and the buccal and labial side of the mandibular ridge, over the mandibular ridge, and the area between the lingual side of the mandibular ridge and the outer wall of the dam, then allowing the impression material to set and then removing the dam and the set impression material.

No references cited. 

